EP0623979B1 - Oscillateur a laser - Google Patents

Oscillateur a laser Download PDF

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Publication number
EP0623979B1
EP0623979B1 EP93922648A EP93922648A EP0623979B1 EP 0623979 B1 EP0623979 B1 EP 0623979B1 EP 93922648 A EP93922648 A EP 93922648A EP 93922648 A EP93922648 A EP 93922648A EP 0623979 B1 EP0623979 B1 EP 0623979B1
Authority
EP
European Patent Office
Prior art keywords
laser beam
mirror
reflecting
folded
reflecting mirror
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP93922648A
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German (de)
English (en)
Other versions
EP0623979A1 (fr
EP0623979A4 (fr
Inventor
Akira Fanuc Mansion Harimomi 3-303 Egawa
Michinori Fanuc Dai-3 Vira-Karamatsu Maeda
Yoshitaka Fanuc Dai-3 Vira-Karamatsu Kubo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fanuc Corp
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Fanuc Corp
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Filing date
Publication date
Application filed by Fanuc Corp filed Critical Fanuc Corp
Publication of EP0623979A4 publication Critical patent/EP0623979A4/fr
Publication of EP0623979A1 publication Critical patent/EP0623979A1/fr
Application granted granted Critical
Publication of EP0623979B1 publication Critical patent/EP0623979B1/fr
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/08—Construction or shape of optical resonators or components thereof
    • H01S3/081—Construction or shape of optical resonators or components thereof comprising three or more reflectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/07—Construction or shape of active medium consisting of a plurality of parts, e.g. segments
    • H01S3/073—Gas lasers comprising separate discharge sections in one cavity, e.g. hybrid lasers
    • H01S3/076—Folded-path lasers

Definitions

  • the present invention relates to a laser oscillator in which a laser beam is emitted from a folded-type resonator, and in particular, to a laser oscillator which is capable of simply providing a circularly polarized laser beam.
  • a gas laser oscillator such as a carbon dioxide gas laser oscillator can provide high efficiency and high output power, so that it has widely been employed in a laser beam machining field.
  • the aforesaid carbon dioxide gas laser oscillator a CO 2 molecule which is used as a laser medium is excited by a discharge generated in the resonator.
  • an electric power supplied for the discharge is subject to limitation due to a durability of members constituting an excitation section and a rise of gas temperature caused by an excitation.
  • the aforesaid laser needs to enlarge an output beam diameter due to limitation of light-proof strength of an output mirror. For this reason, it is necessary to make an optical path of the resonator long in order to obtain high output power; as a consequence, the laser system becomes too large as a whole.
  • most of the laser oscillators are constituted such that the optical path of the resonator is multitudinously folded back so that an entire length of the laser oscillator becomes short.
  • Fig. 5 is a view schematically showing a configuration of a conventional folded-type resonator.
  • a resonator 20 comprises an output mirror 1, a rear mirror 2, excitation sections 3a and 3b, and reflecting mirrors 14a and 14b. All optical axes in the resonator 20 are adjusted so as to be in the identical horizontal plane.
  • the laser beam emitted from the output mirror 1 is polarized, in the vertical direction at an angle of 90° to the horizontal plane, as shown by an arrow 21.
  • a circularly polarized laser beam be irradiated to a workpiece in order to obtain high machining performance rather than a linearly polarized laser beam.
  • a linearly polarized laser beam in the vertical or horizontal direction is generally transformed to a circularly polarized laser beam by means of a mechanism as shown in Fig. 6.
  • Fig. 6 is a view showing a conventional optical system for transforming a linearly polarized laser beam to a circularly polarized laser beam.
  • a laser beam emitted from the resonator 20 is polarized linearly in the vertical direction as shown by an arrow 21.
  • a polarization mirror 5 for polarizing the laser beam linearly at an angle of 45° and a 1/4 wave-length mirror 6 are required.
  • the laser beam which is transformed into a circularly polarized laser beam by the polarization mirror 5 and 1/4 wave-length mirror 6, is further directed in the vertical direction by a mirror 7, and is converged by a condenser lens 8, thus being irradiated to a workpiece 9.
  • the above explanation refers to a case of transforming a linearly polarized laser beam in the vertical direction into a circularly polarized laser beam.
  • a linearly polarized laser beam in the horizontal direction is transformed into a circularly polarized laser beam by the same optical system as described above.
  • the conventional laser oscillator requires at least the polarization mirror 5 and 1/4 wave-length mirror 6 in order to transform a linearly polarized laser beam in the vertical or horizontal direction into a circularly polarized laser beam.
  • the conventional laser oscillator requires the mirror 7 for changing the direction of a laser beam into the vertically downward direction because a workpiece is usually placed on the horizontal plane. In other words, three external mirrors are required. For these additional mirrors, the cost of the laser oscillator, as a whole, becomes high.
  • EP-A-0371781 discloses a laser system whose resonator includes a folded section consisting either of three concave mirrors or a flat and two concave mirrors, which is designed to reflect the incident laser light by 180 degrees.
  • an object of the present invention is to provide a laser oscillator which is capable of simply constituting an external optical system.
  • a light component having a reflecting angle of 90° is reflected toward the third reflecting mirror by the first and second reflecting mirrors; for this reason, an S polarized-light component is reflected.
  • the first and second reflecting mirrors are inclined at an angle of 45° to the vertical plane, so that the S polarized-light component is inclined at an angle of 45° to the horizontal plane.
  • a linearly polarized laser beam inclined at an angle of 45° to the horizontal plane is outputted from the folded-type resonator.
  • an external optical system for transforming a laser beam into a circularly polarized laser beam can be obtained by only a 1/4 wave-length mirror, for example.
  • the external optical system can simply be constituted.
  • Fig. 1 is a view showing a configuration of a folded-type resonator according to the present invention.
  • a folded-type resonator 10 comprises an output mirror 1, a rear mirror 2, excitation sections 3a and 3b, and reflecting mirrors 4a, 4b and 4c.
  • the reflecting mirror 4b is horizontally placed, and arranged so that the center of the mirror 4b coincides with the vertex of an isosceles right triangle in which a line connecting the center of the reflecting mirror 4a with that of the reflecting mirror 4c forms a base thereof.
  • Fig. 2 is a view showing reflecting mirrors 4a, 4b and 4c viewed from the direction shown by an arrow A in Fig. 1.
  • the reflecting mirrors 4a and 4c are inclined at an angle of 45° to the vertical plane.
  • Fig. 3 is a view showing reflecting mirrors 4a, 4b and 4c viewed from the direction shown by an arrow B in Fig. 1.
  • the reflecting mirror 4a is inclined at an angle of 45° to the horizontal plane with respect to an optical axis 3aa of the excitation section 3a.
  • the reflecting mirror 4c is inclined at an angle of 45° to the horizontal plane with respect to an optical axis 3bb of the excitation section 3b.
  • an S polarized-light component of a laser beam excited by the excitation section 3b is reflected toward the reflecting mirror 4b by the reflecting mirror 4c.
  • a P polarized-light component is reflected toward the reflecting mirror 4a by the reflecting mirror 4b.
  • a reflecting-light component of the reflecting mirror 4a is an S polarized-light component.
  • the reflecting mirror 4a is inclined at an angle of 45° to the vertical plane, so that the S polarized-light component, namely a linearly polarized laser beam which is inclined at an angle of 45° to the horizontal plane can be provided.
  • Fig. 4 is a view showing an external optical system for transforming a linearly polarized laser beam into a circularly polarized laser beam.
  • a laser beam emitted from the aforesaid folded-type resonator 10 is polarized linearly in the direction shown by an arrow 11, namely at an angle of 45° .
  • the laser beam is transformed into a circularly polarized laser beam by the 1/4 wavelength mirror 6 while being directed in the vertically downward direction, and is converged by the condenser lens 8, thus being irradiated to the workpiece 9.
  • the conventional external optical system for transforming a laser beam into a circularly polarized laser beam requires three mirrors, that is, a mirror for polarizing a laser beam at an angle of 45° , a 1/4 wave-length mirror, and a mirror for directing a laser beam in the vertically downward direction.
  • a laser beam polarized at an angle of 45° is directly emitted, so that only one 1/4 wave-length mirror 6 need be used. That is, one mirror can be reduced on balance, as one reflecting mirror is added to the folding section.
  • the number of mirrors provided on the outside of the resonator 10 is reduced, so that the manpower required for disassembling, cleansing, adjustment in assembling and the like can be reduced considerably.
  • a laser oscillator with two excitation sections is described.
  • Three or more excitation sections may be employed, being provided with plural folding sections having the same structure as described above.
  • the number of reflecting mirrors increases in the folding section; as a consequence, there is no reduction in the number of the mirrors as a whole.
  • the external optical system is simply constructed, so that operations such as maintenance and assembling can readily be performed.
  • a folded-type resonator of a laser oscillator is constituted so that a linearly polarized laser beam which is inclined at an angle of 45° to the horizontal plane is generated in the folding section.
  • a laser beam emitted from the aforesaid folded-type resonator is a linearly polarized laser beam at an angle of 45° to the horizontal plane.
  • the external optical system for transforming the laser beam outputted from the resonator into a circularly polarized laser beam only a 1/4 wavelength mirror is sufficient, for example.
  • the external optical system is simply constructed.
  • the number of mirrors provided on the outside of the resonator is reduced, so that maintenance operations such as disassembling and cleansing can readily be performed, and the external optical system can further simply be assembled.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Lasers (AREA)
  • Laser Beam Processing (AREA)

Abstract

Oscillateur à laser pouvant émettre une lumière à polarisation circulaire à l'aide d'un système optique externe simple. La partie repliée de son résonateur replié (10) comprend des miroirs réfléchissants (4a), (4b) et (4c). Le miroir réfléchissant (4a) est incliné d'un angle de 45° par rapport à l'axe optique d'une unité excitatrice (3a). Le miroir réfléchissant (4b) est disposé horizontalement, et est placé au sommet de l'angle droit d'un triangle rectangle pourvu de deux côtés égaux, les miroirs réfléchissants (4a) et (4c) étant placés aux autres sommets du triangle. Grâce à cet agencement, la composante de polarisation S de la lumière laser émise par l'unité excitatrice (3b) est réfléchie vers le miroir réfléchissant (4b) par le miroir réfléchissant (4c). En outre, la composante de polarisation P est réfléchie par le miroir réfléchissant (4b). La composante de polarisation S est réfléchie par le miroir réfléchissant (4a). Un faisceau laser possédant une composante de polarisation linéaire indiquée par les flèches (11) est émis par le résonateur replié (10). Par conséquent, à l'extérieur du résonateur replié (10), on peut obtenir aisément un faisceau laser à polarisation circulaire en utilisant uniquement un miroir quart d'onde.

Claims (2)

  1. Oscillateur laser comprenant un résonateur (10) du type à réflexions pour émettre un faisceau laser de telle sorte qu'un axe optique du faisceau laser soit réfléchi plusieurs fois, comprenant des parties d'excitation (3a, 3b), et
       une partie de réflexion présentant un premier et un deuxième miroir réfléchissant plats (4a, 4c), chacun desdits miroirs étant incliné à 45° par rapport à l'axe optique (3aa, 3bb) de la partie d'excitation correspondante (3a, 3b), cet axe optique étant parallèle au plan horizontal et passant par le centre dudit miroir réfléchissant (4a, 4c), et étant en outre incliné à 45° par rapport à un axe qui est perpendiculaire audit plan horizontal et qui passe par le centre dudit miroir réfléchissant (4a, 4c), et un troisième miroir réfléchissant plat (4b) agencé horizontalement, le troisième miroir réfléchissant plat (4b) ayant son centre situé à un sommet d'un triangle rectangle isocèle dont la base est définie par une ligne reliant les centres du premier et du deuxième miroir réfléchissant (4a, 4c) et dont les côtés sont définis par les lignes reliant les centres dudit troisième miroir réfléchissant (4b) au centre dudit premier et à celui dudit deuxième miroir réfléchissant (4a, 4c), le plan défini par ledit triangle étant perpendiculaire audit plan horizontal, de sorte qu'un faisceau laser polarisé linéairement, incliné d'un angle de 45° par rapport au plan horizontal, émerge dudit résonateur (10) du type à réflexions.
  2. Oscillateur laser selon la revendication 1, dans lequel ledit résonateur comprend plusieurs parties de réflexion.
EP93922648A 1992-10-26 1993-10-14 Oscillateur a laser Expired - Lifetime EP0623979B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP287646/92 1992-10-26
JP4287646A JPH06140697A (ja) 1992-10-26 1992-10-26 レーザ発振装置
PCT/JP1993/001494 WO1994010727A1 (fr) 1992-10-26 1993-10-14 Oscillateur a laser

Publications (3)

Publication Number Publication Date
EP0623979A4 EP0623979A4 (fr) 1994-08-18
EP0623979A1 EP0623979A1 (fr) 1994-11-09
EP0623979B1 true EP0623979B1 (fr) 1996-09-04

Family

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Application Number Title Priority Date Filing Date
EP93922648A Expired - Lifetime EP0623979B1 (fr) 1992-10-26 1993-10-14 Oscillateur a laser

Country Status (6)

Country Link
US (1) US5412685A (fr)
EP (1) EP0623979B1 (fr)
JP (1) JPH06140697A (fr)
KR (1) KR100189599B1 (fr)
DE (1) DE69304512T2 (fr)
WO (1) WO1994010727A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07211972A (ja) * 1994-01-20 1995-08-11 Fanuc Ltd レーザ発振器
US5878067A (en) * 1994-08-10 1999-03-02 Fanuc Ltd. Laser oscillator
JPH0856028A (ja) * 1994-08-10 1996-02-27 Fanuc Ltd レーザ発振器
US5867519A (en) * 1996-08-07 1999-02-02 Lumonics Inc. Multiple element, folded beam laser
US5867518A (en) * 1996-08-07 1999-02-02 Lumonics Inc. Multiple element laser pumping chamber
DE19734308A1 (de) * 1997-08-08 1999-02-18 Rofin Sinar Laser Gmbh Gaslaser mit in mehreren Ebenen gefaltetem Strahlengang
DE10033071A1 (de) * 2000-07-07 2002-01-17 Trumpf Lasertechnik Gmbh Laseranordnung für die Materialbearbeitung
CN104242029A (zh) * 2014-09-29 2014-12-24 南京中科神光科技有限公司 一种激光器折叠谐振腔的快速装调方法

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3500681A1 (de) * 1985-01-11 1986-07-17 Hoechst Ag, 6230 Frankfurt Verfahren zur isolierung und reinigung von lymphokinen
JPS62169385A (ja) * 1986-01-21 1987-07-25 Toshiba Corp 横流形ガスレ−ザ装置
JP2514680B2 (ja) * 1988-01-08 1996-07-10 ファナック株式会社 レ―ザ発振装置
US5052017A (en) * 1988-12-01 1991-09-24 Coherent, Inc. High power laser with focusing mirror sets
US5023886A (en) * 1988-12-01 1991-06-11 Coherent, Inc. High power laser with focusing mirror sets
JP2630011B2 (ja) * 1990-04-06 1997-07-16 日本電気株式会社 ランダム偏光Ｈｅ―Ｎｅガスレーザ装置
JP2651263B2 (ja) * 1990-06-11 1997-09-10 ファナック株式会社 レーザ発振装置
JP2846521B2 (ja) * 1992-03-30 1999-01-13 ファナック株式会社 レーザ発振装置

Also Published As

Publication number Publication date
KR100189599B1 (ko) 1999-06-01
US5412685A (en) 1995-05-02
EP0623979A1 (fr) 1994-11-09
DE69304512T2 (de) 1997-01-23
KR940704074A (ko) 1994-12-12
DE69304512D1 (de) 1996-10-10
WO1994010727A1 (fr) 1994-05-11
EP0623979A4 (fr) 1994-08-18
JPH06140697A (ja) 1994-05-20

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